You are interested in finding a 90% confidence interval for the mean number of visits for physical therapy patients. The data below show the number of visits for 10 randomly selected physical therapy patients. Round answers to 3 decimal places where possible.

13, 6, 27, 17, 11, 15, 28, 12, 14, 11

a. To compute the confidence interval use a z or t dustribution?

b. With90% confidence the population mean number of visits per physical therapy patient is between_______and_______visits.

c.If many groups of 10 randomly selected physical therapy patients are studied, then a different confidence interval would be produced from each group. About________percent of these confidence intervals will contain the true population mean number of visits per patient and about________percent will not contain the true population mean number of visits per patient.